DE 37 10 291 A1 discloses a circuit for analog-to-digital conversion of signals of different levels, the circuit arranged with a plurality of voltage dividers. Signals are generated via the voltage dividers and are supplied to comparators connected to a flash converter. An input signal and a reference voltage are applied across the comparators.
DE 10 2008 012 545 A1 discloses a circuit for comparing voltages, the circuit arranged with a plurality of voltage dividers connected to a voltage source. The voltage dividers are each connected to an input of an operational amplifier that is connected to a supply voltage.
A disadvantage of known devices for determining the current intensity on a line is that only above a certain minimum current intensity do the known devices allow an internal electrical supply to a device over the line undergoing determination without considerably reducing the accuracy of measurement. For the purpose of broadening the measurement range, operational amplifiers are frequently used. The operational amplifiers are complex and costly, and require considerable voltage to be supplied. There is a need for a measuring device that allows precise measurement in a broader measurement range with a low complexity, that may be manufactured economically and that overcomes the disadvantages of the prior art.